. ♪ ♪ ♪ the presidential debates are upon us and many people are describing them as mitt romney's last best chance to establish himself as a serious contender worthy of the white house. it's happened before. john kennedy, ronald reagan, george w. bush, all bounced higher in the polls after credible debate performances and went on to win the white house. whatever the outcome, most agree it's the debates that will give us our best opportunity to evaluate these candidates, sort out their positions and separate truth from fiction. not a moment too soon. according to a new survey from the annenberg public policy center at the university of pennsylvania, with a little over a month to go before election day, the public has a lot to learn about the 2012 presidential race. among its findings, only 51% know the romney-ryan plan would preserve traditional medicare for those 55 and older and retain it as an option for those now younger than that. only about half knew that mitt romney would keep the bush tax cuts in place. fewer than half knew that romney and not obama had promised to increase defe